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GC-MS analysis of isolated alkaloids from aerial parts of Leptadenia pyrotechnica (Forsk.) Decne (Asclepiadaceae) was performed. Twenty-four alkaloids and six simple amines were detected for the first time in this plant. Almost all of the alkaloids belonged to pyridine, pyrrole, pyrazine, and indole types. The acute LC50 of the total alkaloids and alcohol extracts estimated by means of brine shrimp toxicity test were 63.09 and 11.89 ppm, respectively. The antitumor activities of these extracts, using potato disc screen, showed good activity represented by −33.6% and −49.3%, respectively.

Investigation of the chemical constituents of Leptadenia pyrotechnica (Forsk.) Decne (Asclepiadaceae) led to the isolation of three cardiac glycosides; 14,19-dihydroxycard-20 (22)-enolide-3-O-[β-d-glucopyranosyl-β-d-digitoxoside] C-I, 14,19-dihydroxycard-20 (22)-enolide-3-O-[β-d-glucopyranosyl-β-d-glucopyranoside] C-II and 14,19-dihydroxycard-20 (22)-enolide-3-O-β-d-digitoxoside C-III. The isolation and identification of these compounds were carried out using rotation locular counter current chromatography (RLCCC), high performance liquid chromatography (HPLC). The structures of the isolated compounds were established by fast-atom bombardment (FAB) and electrospray ionization (ESI) mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopic analysis. The acute toxicity studies of the cardiac glycosides and total alcohol extracts were examined by brine shrimp. Their lethal concentration 50 (LC50) were 18.84 and 11.89 ppm, respectively. The antitumor activity potato disk assays of the cardiac ...

An investigation of Leptadenia pyrotechnica (Forsk.) Decne (Asclepiadaceace) chemical constituents led to the isolation of six flavonoids, kaempferol-3-O-α- l-rhamnopyranosyl (1999→699)-O-β-d-glucopyranoside (E-I.1), kaempferol-3-O-β-d-rhamnopyranosyl (1999→699)-O-β-d-glucopyranoside (E-I.2), texasin-7-O-β-dglucopyranoside E-II.2, kaempferol-3-O-β-d-glucopyranoside (E-III.1), kaempferol (E-IV.1) and kaempferide3-O-α-l-rhamnopyranosyl (1999→699)-O-β-d-glucopyranoside (E-I.1a). The isolation of these compounds was carried out using Sephadex LH-20 low pressure liquid chromatography (LPLC), preparative paper chromatography (PC), and high performance liquid chromatography (HPLC). The chemical structures of the isolated compounds were established by mass spectrometry (FAB- and EI- techniques), nuclear magnetic resonance NMR ( 1 H-, 13 C- and COSY) spectral data and ultraviolet (UV) spectroscopic techniques. The acute toxicity of total alcoholic and total flavonoid extracts were examined by brine shrimp. The LC 50 values were 11.89 and 84.14 ppm for the total alcoholic and total flavonoid extracts, respectively. The mortality rates of the isolated flavonoid fractions of E-I, E-I.1, E-I.2 represent the higher percentages of mortality compared with the rest of the flavonoid fractions. The plant exhibited activity as an antitumor agent in the initial potato disc screen.

Calotropis procera (Ait.) R.Br. (Asclepiadaceae) is a shrub or small tree that grows wild in Egypt. Calotropis acts as a purgative, anthelmintic, anticoagulant, palliative (in problems with respiration, blood pressure), antipyretic, and analgesic, and induces neuromuscular blocking activity. Little research has been done to study the electrophysiological effects of this plant's extracts on cardiac, smooth, and skeletal muscle activities.The present study was conducted to determine the phytochemical composition and the effect of the total alcohol extract of the shoot of the plant, which contains almost all of C. procera's cardiac glycosides, flavonoids, and saponins. Also, this study attempted to throw more light on the electrophysiological effects of the plant extracts on cardiac, smooth, and skeletal muscle activities and to clarify the mechanism(s) of their observed action(s).The aerial parts of the plant were air dried and their ethanol extracts partitioned with successive solvents. Cardiac, smooth, and skeletal muscles were used in this study to investigate the physiological and pharmacological effects of the plant extracts from different solvents. The data were analyzed by paired t-test.The phytochemical investigation of Calotropis procera revealed the presence of cardenolides, flavonoids, and saponins. The effects of ethanol, n-butanol, and ethyl acetate (EtOAc) extracts were each evaluated on isolated toad heart and their mechanisms of action determined. Perfusion with 2 μg/mL ethanol, 0.2 μg/mL butanol, and 0.2 μg/mL EtOAc extracts caused a significant decrease in heart rate (bradycardia), significant increase in the force of ventricular contraction, and increase in T-wave amplitude. In addition, the effects of different extracts of the studied plant on smooth muscle and skeletal muscle were investigated in this study. The different extracts and latex of C. procera induced a negative chronotropic effect and decreased the heart rate (HR) of isolated toad heart. The different extracts increased the power of contraction of the duodenum (trace a). Pretreatment with atropine sulfate as a muscarinic receptor blocker abolished the stimulatory effect of the different plant extracts and latex of C. procera (trace b).The present data suggest that ethanol, butanol, and EtOAc extracts of Calotropis procera have negative chronotropism and positive inotropism. Verapamil could abolish the inotropic effect of ethanol as well as that of butanol and EtOAc extracts. Meanwhile, atropine did not abolish the observed negative chronotropic effect. The ethanol extract increased the power of contraction of rabbit duodenum, but atropine abolished this effect. It also decreased the skeletal muscle contraction; this effect could be through blocking of the nicotinic receptors. Butanol and EtOAc extract data for smooth and skeletal muscles are very close to those for the corresponding ethanol extract of the studied plant. The present data for C. procera indicate its direct action on the myocardium, its increase of smooth muscle motility, and its relaxation of skeletal muscle contraction. The chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.The present data on the extracts of C. procera indicate a direct action on the myocardium, stimulatory effect on smooth muscle motility, and relaxant action on skeletal muscle contraction. Chemical constituents could directly affect the cell membrane probably through receptors coupling to G proteins. They regulate the ion channel physiology as in the myocardium.